Ellipsograph instrument



A. M. JOHNSON 2,926,423 ELLIPSOGRAPH INSTRUMENT March 1, 1960 Filed March 18, 1957 mnunuunm.. a 23 25 24 as 34 v 4a 4846 INVENTOR.

ARTHUR M.JOHNSON ATTORNEY U it at P te 2,926,423 ELLIPSOGRAPH INSTRUMENT Arthur M. Johnson, Greensboro, N.C. Application March 18', 1957, Serial No. ans 8 Claims. (Cl. 33-30 The present invention relates to' an ellipsograph instrument and relates more particularly to an improvement in: an ellipsograph instrument in which. a novel broadrange calibrated beam supporting a drafting instrument carrying carriage is rotatably supported on a guiding framework.

The ellipsograph instrument of this invention is 'designed to be capable of describingellipses having vir: tually an infinite number of ratio combinations, within the limitations of the instrument, for the major and minor axes; and wherein the instrumentis capable of describing very smallellipses as well as largeellip's'es'.

Another object of this invention is to provide an ellip sograph which does not require numerous reference po-' sitions or lines for guiding the ellipsograph.

It is also an object of this invention to provide an ellipsograph which supports a rotatable calibrated beam having a pivot point on which the beam is rotatable and a drafting instrument supporting carriage rotatably mounted and slidable for various size ellipses on the calibratedbeam. 1

Yet another object of this invention is the provision of an ellipsograph in which a portable framework stand rotatably supports a calibrated beam that is centered at the intersection of the majo'r andrninor axes of an ellipse and the calibrated beam supports a slidable and rotatable carriage on which carriage a drawing member is mounted.

2,926,423 Patented Mar. 1, 1969 "legmember is a foot 21' having a notch 22 therein for coincidental alignment ;on the projected XX axis which represents the major axis of an ellipse. The other end ofthe member 18 has secured thereon a depending step shaft. 23 at the end of which is a first bevel gear 24 that-isfixed on the shaft.

Calibrated beam. 13 extends horizontally and is rotatably mounted below the horizontal member 18 on the shaft". 23 through an opening in the angle plate Bracket'ZS that extends normal to the-beam. Bracket 25 is formed on the beam intermediate the beam length. The calibrated main portion 26 of beam 13 consists'of two sections on which are inscribed a lower scale 27 hgaving thereon inscribedi'indicia representing the length of. the major axis of an ellipse, and an upper scale 29 having indi cia inscribed thereon corresponding to various angular projectionsof an ellipse with an elongated guide slot 2'8positioned intermediate the scales 27 and 29. The setting on thescale 27 indicates the full length of the major axis of an. ellipse. At one end of the beam there is a free end 30 that a right angle end 31 with a shaft supporting section 33 at a right angle to the cali- ,brat ed portionof the beam and a terminal finger grasp portion 34 is mounted on the section 33. The other end of the beam 13 has a horizontal section 35 in which there is a return offset 36 in order to make the beam coincide with the plane that includes the axis of the Still'another object. of this invention is to provide 7 an ellipsograph having a calibrated beam in which an offset centeringleg that is rotatable with a calibrated beam affords a broader range'of ellipses to be drawn.

A further object of this invention'is toproVide an ellipsograph instrument that is simple to operate, one that is sturdy in construction and may be readily adapted for, either a pencil, pen..or scribing device.

Other and further objects and many of the attendant advantages of this invention will" become more readily apparent as the inventiong becomes better understood from the' following detailed description takeni n corn- Fig. 3 is an enlarged partial longitudinal sectional" view of a writing member of the ellipsograph disclosed within the circle in Fig. 2.

Referring to'the drawing, there is illustrated in 1.

an ellipsograph instrument 10 shown -in one operating position. upon partially executing an ellipse 11 with the components of the ellipsograph comprising a. supporting framework 12 on which a calibrated beam 13 is rotatably supported with the beam 13 having a groundengaging leg member and pivot point'14 and a drawing shaft 23. The horizontal portion 35, the vertical reach '35, and theel ongated horizontal reach 37 from which the downwardly extending ground-engaging leg 39 projects forms an opening 33 between the horizontal reaches 35 andi37 which opening is for a purpose to be described hereinafter. The ground-engaging leg 39 has a tap ered pivot point 40 that is in axial alignment with the axis of shaft 23. It has been found desirable to extend the point 4 0 slightly. to compensate for some penetration into av jwriti ng surfa ee on which the ellipsograph. is mounted so that the calibrated beam and the horizontal member 18 maybe level when supported during operation. 1

As more clearly showninFig. 2, the bracket 25fis provided with a web 40 thathas an opening to rotatably support in a fixed position one end of a square shaft 41 in the bearing42 The other end of the shaft 41 extends throughthe vertical web of the rearwardly extending angle bracket 43 that is connected to the forwardly extending and upwardly projecting rider 44.

tion thereon. A rear plate 46 is'retained against the back of'the beam withthe knurled head screw 4-7 passing through the slot 28 for threadable engagement with the capped opening (not shown) in the rear plate 46.

The shaft 41 at the bracket 4-3 has mounted there- The V end o f shaft 41 is fastened to the section 33 for rota- 50 engaging with the gear 48 has a downwardly projecting shaft 51 that extends through the spacer 52 to which the shaft is securely fastened and the shaft 51 extends through the elongated slot 53 in the horizontal web 54 of the carriage 15. A knurled head screw 55 extends through the web slot 53 and is threadably fastened to the spacer 52 for a purpose to be described hereinafter. graduated on the front face thereof in increments which represent the numerical difference between the length of the major axis and the length of the minor axis. In the embodiment illustrated the scale is represented as one-fourth to one. Therefore, with a major axis of 7 inches and a minor axis of 3 inches a resulting setting on the scale would be placed at the position marked 4. An indicia mark 57 is inscribed on the front of the spacer 52 with the mark being in direct alignment in the plane of the axis of shaft 51.

A vertically mounted sleeve 58 is securely fastened to one end of the carriage web 54. The sleeve 58 is tubular and recieves therein an insert sleeve 59 which is in threaded engagement therewith. A writing instrument supporting sleeve 60 is telescopically received in the sleeve 59 and has a spring 61 therein and a projecting stud 62 that extends through the elongated slot 63 in the sleeve 59 to permit the writing instrument, such as a lead point 64 to be resiliently supported in a projected position. Suitable knurled nuts 65 and 66 retain the sleeve members constituting the writing instrument in position in a conventional collet grip manner.

In one preferred embodiment of the present invention the gears 24 and 49 are bevel gears having a 2 to 1 ratio with the gears 48 and 50 being miter gears having a l to 1 ratio. It will be readily apparent that for use with small ellipses, the carirage during rotation will be introduced into the opening 38 that is formed in the ground-engaging leg member 14, thus providing an appreciably increased range for describing small ellipses.

Carriage'lS has a vertical web 56 that is V In operation, assuming that an ellipse having a major axis of 7 inches and a minor axis of 3 inches is desired, the setting will be as follows: The index mark 57 on the spacer 52 is placed directly in line with the calibrated mark on the carirage scale appearing on the web 56 indicating the difference in length between the major and minor axes by initially loosening the knurled head screw 55 and sliding the carriage 15 through the elongated slot 53 until the index mark 57 is directly over the calibration that is marked 4. Retaining the setting performed on the carriage as above, the knurled head screw 47 is then loosened, and the rider 44 which supports the entire carriage is then shifted so thatlthe zero (0) graduation having the arrowhead 67 thereon points to the lower scale at the position that represents the length of the major axis. The knurled screw 47 is then tightened to lock the assembly in position. In this example, the arrow head 67 on the carriage web 56 will be positioned so that the arrowhead points to the mark 7. The pivot point on the ground-engaging leg 14 will then be placed on the intersection 0 of the major axis XX and the minor axis YY with the notch 22 on the foot 21 registering with the XX axis projected. With one hand the grip 19 is supported to stabilize the instrument in a vertical plane. The other hand may then engage the portion 34 on the free end of the beam 13. Upon rotating the beam about the pivot point 40 the fixed gear 24 that engages the gear 49 will cause the gear 49 to rotate the shaft 41 which shaft in turn will rotate the gear 48 that is on the same shaft. Upon rotation of the gear 48, the gear afiixed to the spacer 52 will be driven. Since the shaft 51 extends through the slot 53 and the knurled screw passes through the slot 53 to engage the spacer, the carriage 15 will be rotated upon rotation of the gear 50. Clockwise rotation of the calibrated beam will produce counterclookwise rotation 'ondgear on, the beam shaft, said first gear driving the of the carriage on which the writing instrument is attached.

Where conjugate axes are known as where an ellipse of a given size is to be described in projection at a designated angular disposition, the instrument setting is as follows for an ellipse designated as a 7 inch by 60 degree ellipse: A setting obtained from a chart corresponding with the particular instrument will be employed as indicated below for the instrument illustrated and the setting indicated for a 7 inch major axis at 60 degrees indicates a reading of F on the upper scale .29; To obtain this setting the knurled screw 47 is loosened and the edge 68 on the rider 44 is placed at the F graduation on the upper scale 29. Thereafter the knurled screw is locked in position. Also, the knurled screw 55 is loosened and the carriage 15 is displaced so that the arrowhead 67 points to the major axis on the lower scale 27 at the mark 7 and the knurled screw 55 is then tightened. The operation for making the construction is as above described.

The following chart is illustrative of one ellipsograph instrument embodying the inventive concept wherein the chart tabulates various settings for ellipses in projection drawing.

Obviously, many modifications and variations may be made in the construction and arrangement of the frame, the calibrated beam, and the carriage as well as modifications made to the mounting for the components without departing from the real purpose and spirit of this invention. It is, therefore, to be understood that within the scope of the appended claims many modified forms of the present inventive concept as well as the use of equivalents and alternatives may be reasonably included and modifications are contemplated.

What is claimed is:

1. An ellipsograph instrument comprising an open stand having a horizontally extending member and a depending ground-engaging leg at one end of the member and a foreshortened leg at the other end of the member, said fores'hortened leg having a downwardly extending shaft, a calibrated beam horizontally supported and rotatably mounted intermediate the beam length on said member shaft, said beam having a depending groundengaging leg having alcarriage-receiving opening therein, said leg of the beam having aground-engaging pivot point coaxially aligned and in spaced relation with said member shaft, a first gear fixedly mounted on said member shaft, a shaft rotatablysupported on said beam, a second gear on the beam shaft engaging said first gear and a third gear supported in spaced relation to said secsecond gear and shaft upon rotation of the beam, the third gear being slidable on the beam shaft, a drawing instrument supporting carriage rotatably suspended from said beam intermediate its length and adjustable along said beam, a fourth gear fixed to said carriage and engaging said third gear on said beam for rotating said carriage upon beam shaft rotation, a drawing instrument depending from said carriage, and indicia on said beam and said carriage for setting major and minor axis lengths whereby I foreshortened leg, said beam having a depending leg with a carriage-receiving opening therein, said beam leg having a pivot point coaxially aligned and in spaced relation with said foreshortencd leg, said beam extending horizontally, a first gear mounted on said foreshortened'leg,

a shaft rotata-bly supported on said beam, a gear on the beam shaft in driving contact with the first gear, beam shaft gear being in driving engagement with said first gear, a beam shaft supporting gear spaced from the other gear on the beam shaft and slidable on said shaft, a carriage rotatably supported from said beam intermediate its length and adjustable along said beam, a carriage volving gear fixed to said carriage in driven engagement with the beam shaft slidable gear for revolving said carriag'e, a drawing instrument depending from said carriage, and a scale having indicia on said beam and on said carriage for setting major and minor axis lengths.

3. An ellipsograph instrument comprising a stand having a horizontally extending member and a depending ground-engaging leg at one end of the member and a foreshortened leg at the other end of the member, a calibrated beam swingably mounted on said foreshortened leg, said beam having a depending leg having a return reach to provide a carriage-receiving opening, said leg having a ground-engaging pivot point in line with said foreshortened leg and in spaced relation therewith, said beam extending horizontally beneath said stand member, a shaft rotatably supported on said beam, means on the foreshortened leg to rotate said beam shaft upon rotation of said beam, a gear slidably mounted on the beam shaft in spaced relation to said means, a drawing instrument supporting carriage rotatably supported and adjustably suspended from said beam, a gear mounted on the carriage to engage said slidable gear on said beam supported shaft, a drawing instrument depending from said carriage, and a scale on said carriage and said beam for setting major and minor axis lengths whereby upon rotating said beam the carriage will rotate to describe an ellipse with said drawing instrument.

4. An ellipsograph instrument comprising a stand having a depending ground-engaging leg at one end and a foreshortened leg at'the other end, a calibrated beam rotatably mounted on the foreshortened leg, said beam having a depending leg having a carriage-receiving return bend opening therein, said leg having a ground-engaging pivot point in axial alignment and in spaced relation with said foreshortened leg, a shaft rotatably supported on said beam, means on the foreshortened leg to rotate said beam shaft upon rotation of said beam, a drafting instrument supporting carriage rotatably supported adjustably mounted fromsaidbeam, means on said beam shaft for revolving said carriage, a drawing instrument depending from said carriage, and a scale on said beain and on said carriage for setting major and minor axis lengths whereby upon revolving said beam the suspended carriage will rotate on the beam to describe an ellipse.

5. An ellipsograph drawing instrument comprising a beam supporting stand having a ground-engaging leg and a foreshortened beam supporting leg, a calibrated beam rotatably mounted on the beam supporting leg, one end of said beam extending freely and the other end of said beam having a depending return bend downwardly extending leg, the terminal end of said return bend leg having a pivot about which the beam may rotate, said point being in axial alignment with said beam supporting leg, a gear fixed on said beam supporting leg, a beam supported rotatable shaft extending parallel to said beam, said. beam supported shaft having mounted thereon in 6 spaced relation a pair of gears, one of said pair of ears cooperating with said fixed gear on the beam supporting leg and the other gear of said pair of gears being slidably mounted on the beam shaft, a drawing instrument supporting calibrated carriage rotatably suspended and slidably retained on said beam, said carriage having means thereon for cooperating with said gear slidable on the beam supported shaft, a rider slidably mounted on the beam and connected to said carriage, and means on said carriage for locking the carriage in a selected position on the calibrated beam.

6. An ellipsogr-aph drawing instrument comprising a beam supporting stand having a ground-engaging leg and a foreshortened beam supporting leg, a calibrated beam rotatably mounted on the beam supporting leg, one end of said beam extending freely and the other end of said beam having a depending return bend downwardly extending leg, the terminal end of said return bend leg having a point about which the beam may rotate,- said point being in axial alignment with said beam supporting leg, a beam supported rotatable shaft extending parallel to said beam and mounted thereon, means on the beam supporting leg for rotating said shaft as said beam is rotated about said beam supporting leg, said beam supported shaft having mounted thereon in spaced relation to said shaft rotating means a gear slidable on said shaft, a drawing instrument supporting calibrated carraige rotatably suspended and slidably retained on said beam, said carriage having a gear connected thereto for cooperating with said gear slidable on the beam supported shaft, a rider slidably mounted on the beam, said rider having means for supporting the carriage thereon, and means for guiding the slidable movement of the carriage and releasably locking the carriage in a predetermined position relative to the calibrated beam.

7. An ellipsograph comprising a stand having a groundengaging leg, a calibrated beam rotatably supported from the stand, said beam having a freeend and a groundengaging leg at the other end, said leg having a return bend, a shaft rotatably mounted on the beam, means on the stand for rotating said shaft upon rotation of the beam, a calibrated drafting instrument supporting carriage suspended from said beam and adjustable thereon, said calibrated drafting instrument being operable through the return bend in said ground-engaging leg, and means on said shaft for rotating said carriage upon revolving saidbeam.

8. An ellipsograph comprising a stand having a groundengaging legend a beam supporting leg, a calibrated beam rotatably mounted on the beam supporting leg, said beam having a depending ground-engaging leg at one end, said depending leg having a return bend therein, a shaft rotatably mounted on said beam, means on the beam supporting leg for rotating said shaft, a calibrated carriage adjustably and rotatably suspended from said beam for operation in close proximity to the depending leg for passage of the carriage through the return bend therein, means on said shaft for rotating said carriage upon rotation of said beam on the beam supporting leg, and a writing instrument supported on thecarriage for describing an ellipse upon rotation of said beam and supported carriage.

References Cited in the tile of this patent UNITED STATES PATENTS 333,972 Rummel Jan. 5, 1886 954,476 Spunar Apr. 12, 1910 1,007,910 Baker Nov. 7, 1911 FOREIGN PATENTS 97,701 Germany -i. June 22, 1898 245,774 Germany Apr; 18, 1912 290,611 Switzerland Sept. 16, 1953 488,995 Italy Jan. 9, 1954 

